Electric lamp and socket



Patented May 3, 1949 UNI TED STAT ES RATE NT. 0 PF! CE ELECTRIC LAMP AND SOCKET,

Foster J. 'Trainor;=-Holly Hill, Fla.

Application May 14, 1948,:SerialNo. '27;130"

6 Claims.- (Cl. 176 32) Thisnapplication is-a continuation-in-part of applications .Serial No; 760,761 and Serial NO.

My. invention relatesrto electric lamps and sockets or plugs- :and sockets. At the present time lampbulbs are commonly retained in sockets-zby means ofa screwthread- This constructionis. has a a number of inconveniences and ingaeplacement, the bulomust be gripped sosecurely-that it maybe turned --and this leads to;.compl-ications' in theconstruction of the removed-implement.

Another difficulty incident to thetype of lamp and socketnowin useis'the. objectionable nicety with which the bulb 'must be alined with the socket. in order that the threads: will engage properly. This objection .is particularly important where the .socket is located overhead or in some suchlccation such thattheperson making the replacement. hashis .faculties disturbed.

Another disadvantage to thepr esent type, of-

bulb and socket: resides in the expenditure in time required 'to remove and replace a bulb..

This aspect istparticularly serious in large build.-

ings wherein a very large-number of bulbs require replacement at. frequent intervals.

Another dimcultyinherent in the screw-type lamp andsocket results from poor contact be tween the elements of the lamp and socket due either to improper tightening oithe lamp when installed or subsequent loosening due to vibrations .In either case poor contact results in severe'heating of the contacting. elements and the-adjacent: structure upon which the socket is mounted, thus creating objectionablefusing.

oirthe lamp and socket elements and.- a fire hazard .with respectto the adjacent structure.

Another disadvantage inherent in the screw type lampwplug and socket resides in the fact that/lithe lamp is tightenedtoo. energetically either the plug is twisted with respect to the.

lamp bulb thereby creating .a short circuit or certain. of .the socket parts are twistedwith a resultant short circuit. .In either casea serious inconvenience is occasioned as/ well .asa fire.

Anotherdisadvantage arising from the lamp and socket of .the previous .art. is that. frequently the ;-lamp.and-socket contacting members do not makeagood-contact with the result that arcingoccurs. thereby creating considerable interference iii radio receivers.

The objects of, my invention are to eliminate... the troublesv and disadvantages above disoussech... Howevenr-l .have found that the use-fulnessbf... an improved-type of lamp base and socket-is; hindered 'lllllGSS- thetype of lamp base required is Sddesigned-thatit may be. used intheusual... manner. with the socket of the. prior art.

It is. therefore .an object .to provide electric. lamps-and-sockets which .can be engaged .and disengagedby'simply urging the lamp toward and. away: from. the socket.-

Itis another object otmy invention to provide ailamp base and .socket which are. self aligning; for enga ement.

It issstilllanother. object of my inventiontd, provide a simple lamp plug and socket which... will insure good .contact between .lamp and socket. elements.v

Anotherobject of this invention-is .to providers a.lamp,and..socket whichmay be interengagede. withoutsanytwisting or. danger of dislocationinw either. ,the.-..base-of the lamp .or. parts. of. the-..-. socket.-.

It is still another object of this invention-.to... provideL-a .lamp...bulb .having. .a base which .will engage .withmy. improved socketonthe sockets of the prior art.

It'.is.another object to provide a lamp ,base. and socke't. which are. simple and rugged in design,..and economical .to manufacture.

Furthenieatures .and advantages of my .,in-.

"ventio'n will appear from the following descrips..

tiOn-ofspecies thereof and fromthe drawings Inlthedrawings:

Fig. 1 is a verticalview of my improved lamp and socket showing. parts in section;

Fig. ..2 .is..a.vertical view of. a lamp bulb3provided with..-an. improved-base.- for engagement). with..either. the.socket of this invention orithe... screw-insocket common to the prior art;.

Fig. 3 isa cross sectional view of-a snap ele-.. mentrcomponen-t of the socketin open condition;

and.

Fig. 4 is a cross sectional .view of the snap ele-.. ment of--Fig..3 but-in closed condition.

Referringto Fig. 1, the lamp I comprises .a... glass bulb containing the usual filament which. hasdtsends secured to the ferrule 2 and the tip; 5 of. the .base. The ferrule of. the-base is provided... witha slot] having a lower shoulder 8 for pure. poses which will presently become apparent.

The lamp is engaged with the socket referred to generally by the numeral l8 so that the ferrule and tip portion are telescoped within the hollow space provided within the socket.

To the end that the bulb will be firmly retained in the socket and that proper electrical connection will be insured, I provide a resilient snap element 3 for this purpose. This snap action element is generally of the type defined in copending application Serial No. 760,761. It comprises a dished base 35 having an inner annular ring portion and an outer portion comprising a series of spokes 33 which are integral with and substantially co-extensive with the respective annular ring portion.

The base portion, accordingly has an inner periphery defined by the inner edge of the annular ring portion, and an outer periphery defined by the ends of the spokes.

Intermediate the inner and outer periphery and between the spokes I provide struck up fingers 3|. These fingers extend at a considerable angle, preferably in the neighborhood of ninety degrees to the respective portion of the base from which struck. On the free end of each finger, is provided an inturned prong which is substantially parallel to the plane of the portion of the base to which the respective finger is attached.

In order to impart rigidity between each finger and the respective portion of the base from which struck, I provide a continuous upset or rib 34 in the adjacent portions of the finger and base.

The snap action element has two conditions of stability which are alternate conditions of convexity. It follows that in the upward convex condition the fingers 3| diverge, thereby increasing the space defined by the prongs 32. In the downward convex condition, the fingers 3i converge, thereby decreasing the space defined by prongs 32.

Further, if the snap element is supported by the outer periphery of the base, it becomes apparent that in changing from the upper convex condition to the lower convex condition that the inner peripheral portion and therefore the finger portions move axially downward. This characteristic is particularly advantageous in the instant application.

The socket shell comprises a base portion l3 and a bulb guide section referred to generally by the number 9. At a section between the base portion and guide portion I provide an internal annular groove. In this groove I loosely seat the outer periphery of the snap element with the finger portions directed toward the opening defined by the socket guide portion 9.

In the base portion of the socket I provide the springy contact member M which is connected to terminal 24 via rivet l and strap II.

In the same groove and above the snap element I provide an annular conducting ring 2! for the purpose of connecting the snap element to terminal l9. At this point it is apparent that I have provided a socket in which a snap element gripping means forms one terminal means, and a springy contact member forms the other terminal means for connecting a source of electrical energy to a lamp base or plug.

It is also apparent at this point, that with the snap element in upward convex condition that an annular space is defined by the open prong portions, and if an object is inserted into the socket and urged against the snap element base portion, the snap element base will snap downward and the prongs snap inward as shown in Fig. 4. To

return the snap element to open condition, an upward or outword force applied to the inturned prongs causes the prongs to snap outward and the snap element takes on the condition of Figure 3.

I provide a lamp base or plug for use with my improved socket.

A simple embodiment is illustrated in Figure 1. The lamp has a reduced end portion and a pair of filament leads in the usual manner.

To the reduced end of the bulb I mount a conducting ferrule member 2. The ferrule has a conical end portion in which is affixed an insulating wafer 4 and in the center of which is provided a conducting tip portion. The lamp base so far described is old in the art and is supplied as a unit, the outward configuration of which is a cylindrical portion having an opening at one end, and a substantially conical portion at the other end.

Intermediate the axial length of the cylindrical portion, I provide a groove 1. The axial distance between that part of the conical end which has the same diameter as the open center of the snap element base, and the bottom of the groove is equal to or preferably slightly less than the length of the snap element finger elements.

It follows that the engagement of the lamp base in the socket, necessitates only a direct force. The conical end of the lamp base automatically centers the lamp base, and under the influence of pressure, the snap element is caused to snap downward, thereby causing prongs 32 to snap inwardly to grasp o-r grip in the groove of the lamp base. This last action is accompanied with a downward axial motion which causes the lamp base tip t to establish positive electrical contact with socket contact member 14. The same force causes the outer periphery of the snap element to exert pressure against conductor ring 21 to establish positive electrical contact therewith.

In order to disengage the lamp and socket assembly it is merely necessary to exert a pulling force on the bulb in a direction away from the socket. Engagement of the finger member with the lower shoulder 8 of the lamp plug causes the snap element to snap into upward convex condition thereby causing the inturned fingers 32 to spring apart and release the lamp.

In order that the lamp plug which is adapted to cooperate with my improved socket shall have its usefulness increased to include its use in the sockets of the prior art, I provide the preferred embodiment of Fig. 2. In this embodiment, the lamp I is provided with the metal ferrule 2. This ferrule is provided with the customary screw threads as well as the annular groove 7 already described with reference to the lamp plug of Figure 1.

It follows that the fabrication of lamps in accordance with my improved design does not detract in any way from their usefulness in the sockets of the prior art.

Although the invention has been described with reference to the above described specific embodiments, other modifications are possible. Therefore the invention is restricted only by the appended claims as interpreted in view of the prior art.

What is claimed is:

1. In combination, an electric lamp and a socket, said electric lamp comprising a glass envelop having a neck portion and a base member secured to said neck portion, said base comprising a symmetrical metal ferrule, an insulator, and a conducting tip element, said conducting tip element being axially spaced from said ferrule along the median line thereof, said ferrule having an annular groove spaced from said tip element, said socket including a plurality of gripping means aflixed to a convex snap element, said snap element being in the form of an open geometrical figure to thereby admit the tip element and part of the insulator element of said lamp base and said gripping means adapted to spring inwardly when said snap element is depressed to thereby engage the base annular groove.

2. In combination, a lamp and a socket, said lamp having a base portion provided with at least a groove spaced from the free end thereof and lying in a plane substantially normal to the axis of said lamp, a snap action element having two conditions of stability and having a dished resilient base portion having an open center of dimensions less than the cross-section of the lamp base portion, means supporting the outer edge portion of the snap action element in the socket normal to the axis thereof, upturned fingers affixed to the snap action element intermediate the inner and outer edges thereof and directed toward the open end of the socket, iii-turned prongs afi'ixed to the free end of the fingers, said prongs being of a length to admit the lamp base into the socket when the snap action element is convex toward the open end of the socket, and said fingers being of a length substantially equal to the distance between said lamp base free end and the groove, whereb insertion of said lamp base into said socket engages the snap action base inner edge portion to reverse the convexity thereof to cause said fingers to spring inwardly and the prongs to engage said lamp base groove, and an electrical terminal connected to said snap element to establish electrical continuity with the lamp base portion.

3. An electric plug element comprising a cylindrical ferrule and a substantially conical end portion comprising an insulator and a conducting tip element supported at the end of said insulator, and said ferrule having formed thereon a continuous groove having at least one helical groove portion and a cylindrical groove portion, said cylindrical groove portion having a depth greater than the helical portion.

4. An electric plug comprising a substantially cylindrical metal ferrule and affixed thereto an insulating frusto-conical end portion, a metal contact element supported by the end of the frusto-conical portion, said ferrule being provided with a continuous groove having helical end portions and an intermediate cylindrical portion, said cylindrical portion being deeper than the helical portions and being bounded at the outer edges thereof by the adjacent helical portions.

5. A plug member comprising a cylidrical ferrule member having a frusto-conical end portion, an insulator element affixed to the end of the frusto-conical end portion and a conducting tip member supported by the free end of said insulator member; the outer surface of said cylidrical member being provided with an annular groove intermediate the ends thereof, said groove being defined by side walls in which the side wall most proximate the tip member lies in a radial plane. 6. In combination, a lamp and a socket, said lamp having an envelope with a base aflixed thereto, said base comprising a cylindrical conducting member, and a metal tip member spacedly afiixed to said cylindrical member on the axis thereof by insulation means having a substantially conical surface, said cylindrical conducting member having an external annular groove in a plane normal to its axis; said socket having a pair of terminals and comprising a hollow body defined by bottom and side walls, a groove in said side walls lying in a plane normal to the median line of said hollow body, a flexible metallic snap action device having an outer edge portion, a central opening defined by an inner edge portion and a latching means aflixed intermediate said edge portion, said outer edge portion being seated in said hollow body groove; a conducting member also seated in said groove adjacent said snap action device outer edge on the face there-,

of away from the socket bottom wall, said conducting member being connected to one of said terminals, a contact element supported by the bottom wall of said socket; whereby said lamp base is engaged with said socket by snugly inserting the same thereinto to automatically cause the snap action device latching means to engage the lamp base groove and urge the same downward to thereby establish positive contact between said lamp base tip member and said socket bottom wall contact element.

FOSTER J. TRAINOR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,770,377 Wolfe July 15, 1930 2,172,086 Marszalski Sept. 5, 1939 2,292,242 Sagona Aug. 4, 1942 

